1 Antepartum Testing Study Guide (Chp 26 in both Textbook editions) Instructions: Fill in yellow blanks. Each word in word bank will be used only once. Word Bank Abdominal Accelerations Antepartum 8-10 Lateral Amniotic Ultrasound Direct Transfusion Anemia Breathing Sound Indirect 14 Lung Placenta 6 Reactive Non-reactive Maturity vibration Transvaginal Movements Ten fetal Daily Fetal Movement (Kick Counts) . : easy, non-invasive, inexpensive assessment of fetal activity and well-being. Count the # of _____________ in a 1- 2 hr period til a minimum of ______ movements are counted (actual procedure may vary). Ultrasound : Provides info on fetal activity/gestational age, normal versus abnormal fetal growth, visual help with invasive tests. Two types of ultrasonography: •_________: gel to abdomen, transducer over skin, pillow under head, knees; need a full bladder to push uterus up to view •_________: probe inserted into the vagina; visualize pelvic anatomy in greater detail; early dx of intrauterine pregnancy; ID abnormal in embryo, establish gestational age (1st trimester); no need for full bladder Biophysical Profile (BPP): detailed assessment of the physical and physiological characteristics of the developing fetus to determine normal and abnormal response to stimuli; noninvasive assessment of fetal health based on acute/chronic markers. BPP includes fetal __________ movements, fetal trunk/limb movements, fetal tone, fetal heart rate (FHR) by a non-stress test (NST) and amniotic fluid volume (AFV) by u/s 1 2 Categories/scoring: A score of ______ is considered WNL; if score is _____ or less -associated with fetal asphyxia & increased perinatal morbidity and mortality. (“Modified BPP” includes NST and amniotic fluid volume (AFV) and is now often used for low-risk pregnancies.) Amniocentesis : Obtain sample of __________ fluid which contains fetal cells that can assess fetal chromosomal abnormalities; ___________is used for direct visualization and guidance; needle inserted Trans-abdominally into uterus and amniotic fluid is extracted. Test performed after week ___ of pregnancy. Why? Sufficient fluid for testing without harm to fetus Indications: prenatal dx of genetic and congenital defects; assess fetal ______maturity Complications: Maternal-hemorrhage, infections, labor, abruption, amniotic fluid embolus (AFE), maternal Rh iso-immunization; Fetal-death, hemorrhage, infection, injury, amniotic fluid leak Chorionic Villus Sampling: used for genetic studies, primarily in first trimester. Ideal time to be performed is between weeks 10 – 13. Sterile procedure; 18-20 gauge needle inserted through abdominal wall with ultrasound guidance. Removes a small tissue sample from the fetal portion of the ____________. Carries similar risks as amniocentesis. Percutaneous Umbilical Blood Sampling (PUBS) Used for ______ blood sampling or __________. Helpful to identify specific genetic mutations, fetal blood type, Rh factor, assessment for fetal _______, infection, and thrombocytopenia. Potential complications: miscarriage, hematomas, bleeding, fetal bradycardia, hemorrhage. After procedure, fetal heart rate (FHR) will be monitored continuously for 1-2 hours, and mother should be taught to perform fetal kick counts. Popularity of this procedure is declining due to the current use of less-invasive techniques. Alpha-fetoprotein (AFP) & Quad Screening • Diagnostic only; screening tool for neural tube defects, Down’s • Recommended for all pregnant women • AFP produced by fetal liver-detectable at 14-34 wk gestation • Optimal timing between 15 – 20 weeks • I.D mothers who need definitive dx: amnio/ultrasound • ___High or ___Low AFP levels can be associated with Down’s? (Check one). ___High or ___Low AFP levels can be associated with Neural Tube Defects? (Check one). 2 3 Coombs’: (text & posted handout in Canvas) Blood test to determine if there is a blood incompatibility between mom and baby. __________ Coombs’: performed on maternal blood to detect antibodies in serum. Determines whether Rh-negative client has developed antibodies to Rh antigen; Sensitized Rh negative women develop anti-Rh antibodies that cross placenta in subsequent Rh positive pregnancies and destroy fetal RBCs. ________ Coombs’: done on the fetal blood after birth to identify maternal antibodies attached to fetal red blood cells. The problem is when Rh negative mom has Rh positive baby. Non-Stress Test (NST) : most widely used for __________ evaluation of fetus. A normal, healthy fetus produces characteristic heart rate patterns in response to fetal movement. In healthy fetuses, fetal movement is associated with fetal heart rate (FHR) _________. Indications: Maternal Diabetes mellitus, Chronic HBP, pregnancy-induced HTN, intrauterine growth restriction (IUGR), post-maturity, decreased fetal movement, advanced maternal age. Procedure: Client is reclined or in Semi-fowler’s with slight ______ tilt to optimize uterine perfusion & avoid supine hypotension; FHR recorded with a Doppler transducer and a tocodynameter is applied to detect uterine contractions and fetal movements; tracing is observed for signs of fetal activity and a concurrent acceleration of FHR; Woman may be asked to press a button to record fetal movements felt (will show up on the strip) Interpretation: ________ test 2 or more accelerations of 15 BPM lasting 15 seconds over a 20 minute period; normal baseline rate; moderate variability. _________test: criteria not met after 20 minutes. Vibroacoustic Stimulation: another way to test FHR response. Usually done in conjunction with NST. Uses a combination of ______ and _______ to stimulate or wake the baby. A baseline FHR is secured prior to stimulation, then different methods used to create sounds/vibrations. The fetus is expected to respond to stimuli within 3 minutes, and if not, test may be repeated at 1-minute intervals up to 3 times if no response is noted. Contractions Stress Test (CST): Identifies fetus that is stable at rest, but may show compromise with stress. Contractions decrease uterine blood flow and placental perfusion producing brief episodes of fetal hypoxia & bradycardia (normal reaction). After the contraction is over, a normal healthy fetus will return to baseline heart rate. CST identifies fetus that cannot withstand stress of a normal contraction pattern. Interpretation: Negative: no late decelerations with a minimum of 3 uterine contractions w/in 10 min period; Positive: late decelerations with at least half of contractions. If positive, Mom 3 4 may be hospitalized for further observation. May be performed by either oxytocin stimulation or nipple stimulation. Fetal Lung Maturity (amniocentesis): L/S Ratio Procedure: amniotic fluid obtained via amniocentesis and levels measured Lecithin: most critical alveolar surfactant required for post-natal lung expansion-detectable at 21 weeks; Increases throughout the pregnancy. Sphingomeylin: Pulmonary surfactant that remains constant throughout pregnancy. Lecithin/sphingomyelin ratio: chemical markers of fetal lung ________. Fetal lungs are considered mature around 34-36 weeks. When the L/S ratio reaches 2:1, the infant’s lungs are considered mature. Certain situations cause fetal distress and as a result, fetal stress hormones will be released to increase fetal lung maturity: decreased blood flow through placenta (maternal hypertension), decreased placental functioning, infection, use of corticosteroids. Certain maternal states can decrease lung maturity: gestational diabetes, chronic glomerulonephritis Tests to predict pre-term labor Fetal Fibronectin: Glycoprotein produced by the fetus Predicts pre-term labor If it appears in cervical canal b/w 24 to 34 weeks there is a high risk for pre-term labor Done by swab during vaginal exam at OB visits Nitrazine test: vaginal swab on pH test paper. Turns blue if alkalotic (amniotic fluid) AmniSure ROM (Rupture of Membranes) Test is a rapid, qualitative test for the detection of amniotic fluid in vaginal discharge of pregnant women. The test is indicated for women reporting signs, symptoms, or complaints suggestive of ROM. It is more commonly used today than the Nitrazine or Fern test and is considered 98% accurate. Fern Test: vaginal swab placed on slide. Makes “fern leaf” pattern on slide if amniotic fluid Assessment of cervical length (CL) via TVU (transvaginal ultrasound). Short CL associated with preterm labor. 4
